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Abstract:

According to one aspect, a mobile electronic device having a fuel cell
configured to receive fuel and generate therefrom electrical power for
the mobile electronic device, a fuel tank adapted to store fuel and
provide fuel to the fuel cell, and an energy storage device configured to
provide power to the mobile device. The fuel tank is sized and shaped to
at least partially surround the energy storage device. The fuel tank and
the energy storage device may be in thermal contact.

Claims:

1. A mobile electronic device, comprising: a fuel cell configured to
receive fuel and generate therefrom electrical power for the mobile
electronic device; a fuel tank adapted to store fuel and provide fuel to
the fuel cell, wherein the fuel in the fuel tank is endothermically
activated; and a battery configured to provide power to the mobile
device; wherein the fuel tank is in thermal contact with the batter and
the fuel tank is sized and shape to at least surround at least 75% of the
exterior surface of the battery so as to provide for conductive heat
transfer between the battery and the fuel tank so that heat from the
battery increases the temperature of the fuel in the fuel tank.

2. The mobile electronic device of claim 1, wherein the fuel tank
surrounds at least 90% of the exterior surface area of the energy storage
device.

3. The mobile electronic device of claim 1, further comprising a thermal
element provided in the fuel tank for at least one of heating and cooling
at least one of the energy storage device and the fuel tank.

4. The mobile electronic device of claim 1, further comprising a frame
and wherein the fuel tank is provided as at least part of the frame, and
the frame at least partially surrounds the fuel cell.

5. A mobile electronic device, comprising: a fuel cell configured to
receive fuel and generate therefrom electrical power for the mobile
electronic device; a fuel tank adapted to store fuel and provide fuel to
the fuel cell; and an energy storage device configured to provide power
to the mobile device; wherein the fuel tank is sized and shape to at
least partially surround the energy storage device.

6. The mobile electronic device of claim 5, wherein the fuel tank and the
energy storage device are in thermal contact.

7. The mobile electronic device of claim 6, wherein the fuel tank and the
energy storage device are at least partially in direct thermal contact.

8. The mobile electronic device of claim 5, wherein the fuel tank
surrounds at least 50% of the exterior surface area of the energy storage
device.

9. The mobile electronic device of claim 6, wherein at least 50% of the
exterior surface area of the energy storage device is in thermal contact
with the fuel tank.

11. The mobile electronic device of claim 5, further comprising a cover
for securing the energy storage device to the fuel tank.

12. The mobile electronic device of claim 5, further comprising a thermal
element provided in the fuel tank for at least one of heating and cooling
at least one of the energy storage device and the fuel tank.

13. The mobile electronic device of claim 5, wherein at least one of the
surface interfaces between the energy storage device and the fuel tank is
sized and shaped to enhance heat transfer therebetween.

14. The mobile electronic device of claim 5, wherein the fuel in the fuel
tank has a high heat capacity.

15. The mobile electronic device of claim 5, wherein the fuel in the fuel
tank is endothermically activated.

16. The mobile electronic device of claim 5, further comprising a frame
and wherein the fuel tank is provided as at least part of the frame.

18. A mobile electronic device, comprising: a fuel cell configured to
receive fuel and generate therefrom electrical power for the mobile
electronic device; a fuel tank adapted to store fuel and provide fuel to
the fuel cell; and an energy storage device configured to provide power
to the mobile device; wherein the energy storage device is sized and
shape to at least partially surround the fuel tank.

Description:

FIELD

[0001] Embodiments herein relate generally to the field of mobile
electronic devices, and more specifically to mobile electronic devices
having fuel cells with fuel tanks that at least partially surround an
energy storage device such as a battery.

INTRODUCTION

[0002] Fuel cells have become increasing popular in recent years due to
their potential use in electricity generation and relatively low
environmental impact.

[0003] Generally, a fuel cell is an electro-chemical conversion device
that produces electricity from a reaction between a fuel and an oxidant
in the presence of an electrolyte located therebetween. In operation, the
fuel and the oxidant flow into the fuel cell, producing electricity and a
residue or waste product. For example, in the case of a hydrogen fuel
cell, hydrogen is the fuel, oxygen or air may be used as the oxidant, and
the fuel cell produces electricity along with water residue (in a liquid
or gaseous state). Unlike batteries that store chemical energy in a
closed system, fuel cells consume reactants that require replenishment to
maintain the reaction. Therefore, a fuel cell is normally accompanied by
or coupled to a fuel tank that stores fuel.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 is a schematic view of a mobile electronic device with a
fuel cell having a fuel tank that surrounds a battery according to one
embodiment;

[0005] FIG. 2 is a schematic side-view of a fuel tank surrounding an
energy storage device according to another embodiment;

[0006]FIG. 3 is a schematic end view of the fuel tank and energy storage
device of FIG. 2;

[0007] FIG. 4 is a perspective view of a fuel tank for surrounding an
energy storage device according to another embodiment with the fuel tank
and energy storage device decoupled;

[0008] FIG. 5 is a perspective view of the fuel tank and energy storage
device of FIG. 4 with the energy storage device received within the fuel
tank;

[0009] FIG. 6 is a schematic view of a fuel tank surrounding an energy
storage device and including a cover according to another embodiment;

[0010] FIG. 7 is a schematic view of a fuel tank surrounding an energy
storage device incorporating a thermal element according to yet another
embodiment;

[0011] FIG. 8 is a schematic view of a fuel tank surrounding an energy
storage device according to yet another embodiment wherein the interface
between the energy storage device and the fuel tank is sized and shaped
to increase the effective surface area therebetween;

[0012]FIG. 9 is a schematic view of an energy storage device surrounding
a fuel tank according to an alternative embodiment;

[0013] FIG. 10 is a schematic view of an energy storage device surrounding
a fuel tank and having a thermal insulating element according to another
alternative embodiment;

[0014]FIG. 11 is a schematic view of an energy storage device surrounding
a fuel tank and a fuel cell according to yet another embodiment;

[0015]FIG. 12 is a schematic side view of a mobile electronic device
having a frame that serves as a fuel tank that surrounds at least one
energy storage device; and

[0016]FIG. 13 is a schematic front view of the mobile electronic device
of FIG. 12.

DETAILED DESCRIPTION

[0017] Recently, efforts have been made to incorporate fuel cells into
portable electronic devices (also herein called mobile electronic
devices). Efforts have been extended to handheld portable electronic
devices, i.e., devices sized to be carried or held in a human hand (e.g.
smart phones, readers, tablet computers, etc.). Some portable electronic
devices that include fuel cells may also include one or more supplemental
energy storage devices (e.g. a battery or capacitor) to better meet the
varying power demands of the portable electronic device.

[0018] Some energy storage devices, such as batteries, can experience
significant temperature increases while powering a portable electronic
device. Temperature increases may be undesirable, as they may tend to
reduce battery life, decrease efficiency, or interfere with the operation
of the portable electronic device. In extreme cases, high heat may result
in safety concerns, and may risk damage to the mobile electronic device
or make operation of the mobile electronic device uncomfortable for the
user. The following disclosure discusses devices and techniques whereby
the heat can be managed and in some cases even put to good use.

[0019] It will be appreciated that for simplicity and clarity of
illustration, where considered appropriate, reference numerals may be
repeated among the figures to indicate corresponding or analogous
elements or steps. In addition, numerous specific details are set forth
in order to provide a thorough understanding of the example embodiments
described herein. It will be understood by those of ordinary skill in the
art that the embodiments described herein may be practiced without these
specific details. In other instances, well-known methods, procedures and
components have not been described in detail so as not to obscure the
embodiments described herein. Furthermore, this description is not to be
considered as limiting the scope of the embodiments described herein in
any way, but rather as merely describing the implementation of some
various embodiments as described herein.

[0020] Some of the embodiments described herein refer to a mobile
electronic device. Generally, a mobile electronic device may be a two-way
communication device with data communication capabilities, and which may
include the capability to communicate in a wireless or wired fashion with
other devices, including other mobile electronic devices. In some
embodiments, the mobile electronic device may include the capability for
voice communications. In some embodiments, the mobile electronic device
may include the capability for data communications.

[0021] Depending on the functionality provided by the mobile electronic
device, it might also be referred to, for example, as a data-messaging
device, a cellular telephone with data messaging capabilities, a wireless
Internet appliance, or a data communication device (with or without
telephony capabilities). Some examples of mobile electronic devices could
include cellular phones, cellular smart-phones, wireless organizers,
personal digital assistants, handheld wireless communication devices,
wirelessly enabled notebook computers, tablet computers and the like.

[0022] The embodiments herein generally relate to mobile electronic
devices that include fuel cells. More particularly, some of the
embodiments herein relate to mobile electronic devices with fuel cells
having one or more fuel tanks that at least partially surround or
encapsulate one or more energy storage devices, such as batteries,
capacitors, etc.

[0023] As briefly discussed above, during use a mobile electronic device
may experience varying levels of power consumption. For example, when a
mobile electronic device is in an idle or "sleep" state, various
components on the mobile electronic device may be deactivated (e.g. the
display screen and radio may be powered off) and the mobile electronic
device may consume low amounts of power. Alternatively, when a mobile
electronic device is in an active state (e.g. when a user is making a
telephone call, or sending and receiving data messages), the mobile
electronic device may consume large quantities of power.

[0024] Accordingly, some mobile electronic devices with a fuel cell also
include an energy storage device (e.g. a battery, a capacitor, etc.) to
help accommodate the peak power requirements of the mobile electronic
device. For example, the size of the fuel cell and fuel tank may be
selected to accommodate most of the power needs of the mobile electronic
device, while an energy storage device may be selected to provide
additional power during periods of high power consumption that exceed the
output capacity of the fuel cell.

[0025] In some embodiments, the energy storage device may be particularly
useful in providing power to the mobile electronic device during a
start-up condition. For example, when a device is initially powered on,
its fuel cell may not be immediately ready to provide the desired levels
of power. Thus the energy storage device can provide power during startup
until the fuel cell becomes fully operational.

[0026] One challenge faced by batteries and other energy storage devices
on mobile electronic devices is that they tend to heat up when in use.
This can be particularly problematic on high bandwidth devices, such as
3G+LTE devices. For example, when a battery is being used to power a
mobile electronic device during peak power consumption (e.g. during a
telephone call in a low signal strength condition), the temperature of
the battery can increase dramatically. For example, during peak power
consumption the temperature in the battery can increase from room
temperature to 45 degrees or more within ten minutes. In some cases, at
least some of this heat increase may be due to heat emanated from other
components in the mobile electronic device, and not due to discharge from
the battery.

[0027] This increase in temperature is generally undesirable, and it can
reduce the life cycle of the battery, decrease battery efficiency, as
well as cause safety or comfort concerns.

[0028] Some mobile electronic devices can be configured to temporarily
deactivate power flow to and from a battery when the battery temperature
exceeds a particular threshold. For example, some mobile electronic
devices are configured to charge a battery at a base rate when the
battery temperature is less than a first temperature, charge at a reduced
rate when the battery temperature is between the first temperature and a
second temperature, and cease charging when the battery temperature
exceeds the second temperature. This "charging cut-off" can be
undesirable, as it can increase charging time. It may also limit the
functionality of the mobile electronic device if sufficient power from
the battery, the charging circuit (or both) is not available to power all
of the desired tasks.

[0029] Accordingly, some of the embodiments as described herein can be
used to reduce the temperature of the battery or other energy storage
device to desired levels during use. This can be useful to inhibit or
reduce the effects of increasing temperature on decreasing battery power
output, reduce or inhibit the occurrence of battery deactivation, and may
in some cases lead to longer battery life.

[0030] Generally, this can be accomplished by providing the fuel tank of
the fuel cell and the battery or other energy storage device in a
configuration wherein heat transfer between the battery and the fuel tank
is facilitated. By providing good heat transfer between the battery and
the fuel in the fuel tank, a heat sink for the battery is provided that
can draw excess heat energy away from the battery.

[0031] In some embodiments, to provide this heat transfer, the fuel tank
can be sized and shaped to at least partially surround the battery. For
example, the fuel tank might surround at least three outer surfaces of
the battery (including two opposing surfaces). In another example, the
fuel tank might surround at least 50% of the exterior surface area of the
battery. In yet another example, the fuel tank might surround at least
75% of the exterior surface area of the battery. In yet another example,
the fuel tank might surround at least 90% of the exterior surface area of
the battery.

[0032] By surrounding the battery with the fuel tank, heat transfer (e.g.
via one or more of conduction, radiation, and convection) between the
fuel tank and the battery tends to be encouraged. For example, thermal
radiation emitted by the battery will tend to be absorbed by the fuel
tank.

[0033] In other embodiments, heat transfer between the battery and the
fuel tank may be facilitated by providing the battery and the fuel tank
in thermal contact. For example, in some embodiments, at least 50% of the
exterior surface area of the battery may be in thermal contact with the
fuel tank. In another example, at least 75% of the exterior surface area
of the battery may be in thermal contact with the fuel tank. In yet
another example, at least 90% of the exterior surface area of the battery
may be in thermal contact with the fuel tank. In other embodiments, three
or more exterior surfaces of the battery may be in thermal contact with
the fuel tank.

[0034] In some embodiments, battery and fuel tank may be at least
partially in direct thermal contact (e.g. the battery and fuel tank may
be in direct contact so that heat energy can flow directly therebetween
via conduction). In some embodiments, the battery and fuel tank may be at
least partially in indirect thermal contact (e.g. the battery and fuel
tank may be separated by another element that facilitates or permits
conductive heat transfer therebetween, for example a heat conductive
material such as a gel, a conductive metal plate, etc.).

[0035] By providing the battery and fuel tank in thermal contact, heat
transfer between the battery and the fuel tank can be encouraged (e.g.
through conduction).

[0036] In some embodiments, the fuel tank may be sized and shaped so as to
at least partially surround the battery and also be in thermal contact
with the battery. This configuration tends to encourage heat transfer
between the battery and the fuel tank using various heat transfer modes
(e.g. conduction and radiation in addition to conduction).

[0037] By providing good heat transfer between the battery and the fuel
tank, undesirable heat can be drawn away from the battery and into the
fuel tank, cooling the battery, which may tend to reduce the thermal
gradient across the battery. Controlling battery temperature may result
in a number of benefits, such as increasing battery efficiency,
lengthening battery life and reducing heat-related swelling of the
battery.

[0038] As the heat energy is drawn into the fuel tank, it will tend to
heat the fuel therein. Accordingly, in some embodiments the selection of
the fuel in the fuel tank may be coordinated with the design and
implementation of the fuel cell on the mobile electronic device.

[0039] In some embodiments, the fuel may be selected to have a high heat
capacity. Accordingly, the fuel in the fuel tank may be able to absorb
large quantities of heat energy from the battery while experiencing a
relatively mild increase in temperature. For example, in some
embodiments, a metal hydride fuel (e.g. Ca0.2Mm0.8Ni5) can
have a heat capacity greater than 820 MJ/m3.

[0040] In other embodiments, a fuel can be selected that is
endothermically released. Thus, as heat energy is drawn from the battery
and heats the fuel in the fuel tank, this may tend to increase the
reaction rate of the fuel and increase the overall performance of the
fuel cell.

[0041] In some embodiments, a fuel can be selected that has both a high
heat capacity and which is endothermically released.

[0042] In some embodiments, the change in reaction rate versus temperature
can be controlled using one or more techniques, such as combining
multiple metal hydrides in the fuel tank, each metal hydride having
specific temperature characteristics or partial-pressure characteristics
(or both).

[0043] Examples of suitable fuels could include endothermic metal
hydrides, and liquid fuels with a high heat capacity (such as butane,
ethanol, methanol, etc). In some embodiments, the mobile energy storage
device and fuel tank can be configured to ensure that the temperature in
the fuel tank is less than the flash point of the fuels so as to inhibit
an explosion or fire.

[0044] Generally, the selection of the fuel and the configuration of the
fuel cell are complementary, and can be based according to the desired
operating characteristics of the mobile electronic device.

[0045] Furthermore, in some cases heat from the battery can be used to
throttle the operation of the fuel cell due to the relationship between
the heat energy from the battery and the release of endothermic fuel.

[0046] In some embodiments, when both the fuel cell and the battery are
operating at high temperatures, large quantities of fuel will tend to be
consumed by the fuel cell, and thus heat energy can be drawn from the
battery to the fuel at a relatively high rate. Conversely, when both the
battery and fuel cell are operating at low temperatures, generally less
fuel will be consumed by the fuel cell (and thus the rate of heat
transfer from the battery may be lower).

[0047] In some examples, the embodiments herein can be integrated with the
design of the fuel cells and mobile electronic devices (e.g. the battery
and fuel tank may be "built-in" to the design of the mobile electronic
device). In other examples, the embodiments herein may be useful as
accessories that can be retrofitted onto existing mobile electronic
devices.

[0048] Turning now to FIG. 1, illustrated therein is a schematic
illustration of a mobile electronic device 10 according to one
embodiment. As shown, the mobile electronic device 10 includes a fuel
cell 12 used to provide at least some of the power to the mobile
electronic device 10. Coupled to the fuel cell 12 is a fuel tank 14 for
storing fuel used by the fuel cell 12. As shown, the fuel tank 14 may be
coupled to the fuel cell 12 using one or more conduits 16. In other
embodiments, the fuel cell 12 and fuel tank 14 may be directly coupled.

[0049] The mobile electronic device 10 may also include one or more
reagent storage tanks (not shown) for storing the waste products
generated by the fuel cell 12.

[0050] In this example, the mobile electronic device 10 also includes an
energy storage device in the form of a battery 18. The battery 18 is
configured to also provide power to the mobile electronic device 10
depending on the operating characteristics of the mobile electronic
device 10 (e.g. during startup, peak power consumption, or at various
other times). Generally, the battery 18 could be any suitable battery for
use with a mobile electronic device, and which may benefit from
temperature control (e.g. to improve performance and increase safety).
Some examples could include a lithium-ion battery, a metal hydride
battery, a polymer battery, a silver zinc battery, a zinc-air battery, a
solid-state battery, etc.

[0051] As shown, the fuel cell 12 and battery 18 are electrically
connected to one or more loads (illustrated generally as load 20). The
load 20 can represent various components of the mobile electronic device
10, such as a display screen, power amplifiers (e.g. for radio
transmission), audio output devices, processors, etc. In some cases, the
load 20 may include a battery charger for charging the battery 18 (for
example, the fuel cell 12 could power a battery charger for recharging
the battery 18).

[0052] As generally discussed above, when the battery 18 is used to power
loads 20 on the mobile electronic device 10, the temperature of the
battery 18 tends to increase. Accordingly, in this embodiment the fuel
tank 14 is sized and shaped so as to act as a heat sink for the battery
18.

[0053] In particular, as shown in FIG. 1, the battery 18 is at least
partially surrounded or enclosed by the fuel tank 14. In this embodiment,
all four outer surfaces 21, 23, 25 and 27 of the battery 18 are
surrounded by the fuel tank 14 (e.g. at least 90% of the battery 18 is
surrounded by the fuel tank 14). Thus, heat radiating from the battery 18
will tend to be absorbed by the fuel tank 14. In other embodiments, the
fuel tank 14 may surround less of the surface area of the battery 18. For
example, the fuel tank 14 might surround at least 50% of the exterior
surface area of the battery 18. In yet another example, the fuel tank 14
might surround at least 75% of the exterior surface area of the battery
18.

[0054] Furthermore, in this embodiment the battery 18 and fuel tank 14 are
in direct thermal contact on all exterior surfaces 21, 23, 25 and 27 of
the battery 18 (e.g. at least 90% of the exterior surface area of the
battery 18 is in direct thermal contact with the fuel tank 14).
Accordingly, heat energy from the battery 18 can be conducted away from
the battery 18 and into the fuel tank 14 (and thus into the fuel in the
fuel tank).

[0055] In other embodiments, the fuel tank 14 may be in thermal contact
with less of the surface area of the battery 18. For example, at least
50% of the exterior surface area of the battery 18 may be in thermal
contact with the fuel tank 14. In another example, at least 75% of the
exterior surface area of the battery 18 may be in thermal contact with
the fuel tank 14.

[0056] In other embodiments, the fuel tank 14 and battery 18 may be at
least partially in indirect thermal contact.

[0057] In some embodiments the fuel in the fuel tank 14 may be a fuel that
is endothermically released. Thus, as heat energy is drawn from the
battery 18 and heats the fuel in the fuel tank 14, the rate of reaction
of the fuel can actually increase, tending to result in higher output
from the fuel cell 12.

[0058] In some embodiments, (e.g. if the fuel is butane or methanol),
pre-warming the fuel may also lead to better efficiency for the fuel cell
12 and higher power output.

[0059] In some embodiments, the fuel tank 14 may be made of suitable
materials configured to withstand the temperatures experienced due to
heat transfer between the battery 18 and the fuel tank 14. For example,
the fuel tank 14 may be made of metals, high-temperature plastics, etc.

[0060] Turning now to FIGS. 2 and 3, illustrated therein are side and end
views, respectively, of a fuel tank 42 and energy storage device
according to another embodiment. In this example, the energy storage
device 44 (e.g. a battery, capacitor, etc.) has rectangular cross
sections, and has six surfaces 41, 43, 45, 47, 48 and 49.

[0061] As shown, the fuel tank 42 surrounds five of the six surfaces (e.g.
41, 43, 45, 47 and 49) of the energy storage device 44. However, the
sixth surface 48 is exposed and is not surrounded by the fuel tank 42.
Furthermore, the same five surfaces (e.g. 41, 43, 45, 47 and 49) of the
energy storage device 44 are in direct thermal contact with the fuel tank
42.

[0062] In this embodiment, the energy storage device 44 may be
electrically connected (e.g. via surface 45) to feed through contacts 46
that pass through the fuel tank 42. The contacts 46 can be used for
electrically coupling the energy storage device 44 to one or more loads
on a mobile electronic device. This arrangement may be useful, for
example, to allow the energy storage device 44 to be inserted into the
fuel tank 42 without removing or replacing any battery covers on the
mobile electronic device.

[0063] In other embodiments, the exposed surface 48 of the energy storage
device 44 may be electrically coupled to a load after the energy storage
device 44 has been received within the fuel tank 42, such as by placing
an electrically conducting cover over the exposed surface 48.

[0064] Turning now to FIGS. 4 and 5, as shown an energy storage device 54
may be configured to be removably inserted into an opening 56 of a fuel
tank 52 on a mobile electronic device. In this manner, the battery or
energy storage device 54 can be separately removed from the mobile
electronic device without removing the fuel tank 52.

[0065] In some embodiments, the mobile electronic device could be
configured to provide "hot-swapping" of the energy storage device 54
(e.g. a battery) without the need to turn off the mobile electronic
device or remove the fuel tank 52 from the mobile electronic device. For
example, when the mobile electronic device is powered on and operating in
a mode where the desired power can be provided by the fuel cell (i.e.
such that the battery need not be supplying power to the mobile
electronic device), the battery or energy storage device 54 could be
removed and replaced with a different battery or other energy storage
device.

[0066] In some embodiments, hot-swapping of batteries may be possible
while the mobile electronic device is operating in a high power mode
(e.g. that exceeds the capacity of the fuel cell) if a second energy
storage device is also provided to supply power to the mobile electronic
device. For example, if the mobile electronic device also includes a
capacitor or a "super-capacitor" that can provide power thereto, the
battery or other energy storage device 54 may be removed during a high
power condition.

[0067] Turning now to FIG. 6, in this embodiment a fuel tank 62 of a fuel
cell is configured to surround an energy storage device 64. In
particular, as shown the fuel tank 62 surrounds and is in thermal contact
with at least three surfaces 61, 63 and 65 of the energy storage device
64. Depending on the size of each surface, this may amount to various
proportions of the exterior surface. For example, in some embodiments
this may be at least 50% of the exterior surface area of the energy
storage device 64, at least 75% of the exterior surface area of the
energy storage device 64, more than 75%, or less than 50%.

[0068] This embodiment also includes a cover 66. The cover 66 may help to
secure the energy storage device 64 to the fuel tank 62 to inhibit
disengagement thereof.

[0069] For example, in some embodiments, the energy storage device 64 may
be secured to or a part of the cover 66 so that the energy storage device
64 may be inserted and removed from the fuel tank 62 by inserting and
removing the cover 66, respectively.

[0070] In other embodiments, the cover 66 and energy storage device 64 may
be separate components.

[0071] In some embodiments, the cover 66 may be thermally insulating and
may inhibit heat on a rear surface 67 of the energy storage device 64
from being drawn away from the energy storage device 64.

[0072] In other embodiments, the cover 66 may be thermally conducting so
that heat from the energy storage device 64 emitted by the rear surface
67 may tend to be transmitted through the cover 66 by conduction (e.g. to
the ends 62a, 62b of the fuel tank 62).

[0073] In some embodiments, the cover 66 may include one or more
electrical connectors for electrically coupling the energy storage device
64 to the mobile electronic device.

[0074] Turning now to FIG. 7, in this embodiment a fuel tank 72 surrounds
all four sides (71, 73, 75, and 77) of an energy storage device 74, with
thermal contact with three of the surfaces of the energy storage device
74 (e.g. surfaces 73, 75, 77). In this embodiment, a thermal element 76
is also provided within the fuel tank 72 adjacent the energy storage
device 74. In particular, the thermal element 76 is between the first
exterior surface 71 of the energy storage device 74 and an opposing inner
surface 79 of the fuel tank 72.

[0075] In some embodiments, the thermal element 76 may be used to
selectively heat the energy storage device 74 or the fuel tank 72 or
both. For example, the thermal element 76 may be used to heat the fuel in
the fuel tank 72. This may be beneficial during a startup condition, as
it can assist the fuel in the fuel tank 72 in reaching a desired
operating temperature (e.g. where the fuel is endothermically activated
or where pre-warming of the fuel may provide performance advantages).

[0076] In other embodiments, the thermal element 76 may be used to
selectively cool the energy storage device 74 or the fuel tank 72 or
both. For example, the thermal element 76 could be used to cool the
energy storage device 74 during use, or to further inhibit the
temperature of the energy storage element 74 from exceeding a threshold
value (e.g. 45 degrees Celsius).

[0077] Turning now to FIG. 8, in some embodiments the surface interfaces
between the energy storage element and the fuel tank can be enhanced to
facilitate heat transfer therebetween. As shown, for example, the outer
surfaces of an energy storage device 78 may have a plurality of ridges
80, with complementary features being provided on the inner surfaces of
the fuel tank 72. These ridges increase the effective surface area
between the fuel tank 72 and the energy storage device 74, and can
therefore increase the rate of heat transfer therebetween.

[0078] It will be appreciated that other surface features could be used to
achieve a heat-transfer enhancing effect (e.g. the surfaces could have
other patterns or features, such as waves, roughened textures, etc.). In
yet other embodiments, surface coatings, conducting gels or inserts could
be provided between the energy storage device and the fuel tank to
facilitate the rate of heat transfer therebetween.

[0079] Turning now to FIG. 9, in an alternative embodiment, it may be
desirable that the arrangement of the fuel tank and battery are reversed.
For example, in this embodiment the energy storage device 84 (e.g.
battery or capacitor) is sized and shaped to at least partially surround
the fuel tank 82, and which may be in thermal contact therewith. For
example, as shown the fuel tank 72 is surrounded on, and in thermal
contact with, at least four outer surfaces thereof (e.g. surfaces 81, 83,
85, and 87). In this embodiment, a conduit 86 may be provided for
transporting fuel in the fuel tank 82 to a fuel cell (not shown). In some
embodiments, the conduit 86 may also be used to replenish the fuel in the
fuel tank 82.

[0080] This arrangement may be beneficial depending on the configuration
of the fuel cell and mobile electronic device. For example, it may be
desirable that not all of the heat energy from the energy storage device
84 be directed into the fuel tank 82. Accordingly, in some embodiments
one or more outer surfaces (e.g. surface 89) of the energy storage device
84 could be allowed to radiate outwardly, be placed in contact with
another heat sink, etc.

[0081] Turning now to FIG. 10, in other embodiments the energy storage
device 84 may be at least partially surrounded by a thermal insulating
element 88. For example, the thermal insulating element 88 may be
provided to inhibit heat from leaving the energy storage device 84 (e.g.
via an exterior surface 89). This may be beneficial when it is desirable
to raise the temperature of a battery (e.g. when the battery is a solid
state battery that has increased efficiencies at some elevated
temperatures, or when a thermally-closed battery-fuel tank system is
desirable). This configuration may also be beneficial to insulate the
fuel tank 82 and energy storage device 84 when they are operating at very
high temperatures. For example, the energy storage device 84 could be a
solid-state battery, and the fuel tank 82 could contain a fuel configured
to operate at several hundred degrees Celsius. Accordingly, the thermal
insulating element 88 may serve to protect other components in the mobile
electronic device or the user or both from the high temperatures in the
fuel tank 82 and energy storage device 84.

[0082] In some embodiments, a mobile device may include a fuel tank that
is sized and shaped to surround or be in thermal contact with (or both)
at least a portion of an energy storage device (e.g. a battery) as well
as a fuel cell.

[0083] Turning now to FIG. 11, in some embodiments, the energy storage
device 94 may be configured to at least partially surround or be in
thermal contact with (or both) a fuel tank 92 and a fuel cell 96. In such
embodiments, one or more conduits 96 may be provided to remove waste
products from the fuel cell 96 or to add oxidant to the fuel cell 96 or
both.

[0084] Turning now to FIGS. 12 and 13, illustrated therein is a mobile
electronic device 100 according to another embodiment. In this example,
the mobile electronic device includes a frame 102 that functions as a
fuel tank. For example, the frame 102 may have one or more hollow
portions that are sized and shaped to receive fuel to be used by a fuel
cell.

[0085] In this embodiment, one or more batteries 104, capacitors or other
energy storage devices can be at least partially surrounded by and in
direct thermal contact with the frame 102. In some embodiments, the frame
102 may also include the fuel cell 106 therein.

[0086] While in some embodiments illustrated herein the energy storage
device is shown as a battery, the energy storage device could in some
cases be a capacitor, a super-capacitor, or another suitable energy
storage device.

[0087] As shown, some of the energy storage devices, fuel tanks and other
components herein have rectangular cross-sectional profiles. However, the
energy storage devices, fuel tanks and other components can generally
have any suitable shape, including cylindrical shapes, spherical shapes,
irregular shapes, etc.

[0088] According to one aspect, there is provided a mobile electronic
device, comprising a fuel cell configured to receive fuel and generate
therefrom electrical power for the mobile electronic device, a fuel tank
adapted to store fuel and provide fuel to the fuel cell, and an energy
storage device configured to provide power to the mobile device, wherein
the fuel tank is sized and shape to at least partially surround the
energy storage device.

[0089] The fuel tank and the energy storage device may be in thermal
contact. The fuel tank and the energy storage device may be at least
partially in direct thermal contact.

[0090] The fuel tank may surround at least 50% of the exterior surface
area of the energy storage device. At least 50% of the exterior surface
area of the energy storage device may be in thermal contact with the fuel
tank.

[0091] The energy storage device may be a battery. The fuel tank may be
sized and shaped to removably receive the energy storage device therein.

[0092] The mobile electronic device may further comprise a cover for
securing the energy storage device to the fuel tank.

[0093] The mobile electronic device may further comprising a thermal
element provided in the fuel tank for at least one of heating and cooling
at least one of the energy storage device and the fuel tank.

[0094] At least one of the surface interfaces between the energy storage
device and the fuel tank may be sized and shaped to enhance heat transfer
therebetween.

[0095] The fuel in the fuel tank may have a high heat capacity.

[0096] The fuel in the fuel tank may be endothermically activated.

[0097] The mobile electronic device may further comprise a frame, wherein
the fuel tank is provided as at least part of the frame. The frame may at
least partially surround the fuel cell.

[0098] According to another aspect, there is provided a mobile electronic
device, comprising a fuel cell configured to receive fuel and generate
therefrom electrical power for the mobile electronic device, a fuel tank
adapted to store fuel and provide fuel to the fuel cell, and an energy
storage device configured to provide power to the mobile device, wherein
the energy storage device is sized and shape to at least partially
surround the fuel tank.

[0099] The mobile electronic device may further comprise an insulating
element at least partially surrounding the energy storage device. The
energy storage device may at least partially surround the fuel cell.

[0100] One or more of the embodiments as described herein may provide one
or more benefits. Some potential benefits have been briefly described
above (such as the potentials to enable hot-swapping, improve performance
and increase safety).

[0101] Another potential advantage is that fuel cells may be made more
practical sources of energy for portable electronic devices in general,
and handheld devices in particular. A mobile electronic device poses
challenges that may be different for larger-scale (e.g. industrial)
devices, or which may not exist at all in larger or non-handheld devices.

[0102] At least some of the above embodiments may assist with concerns
about weigh and space that may attend smaller electronic devices, by
making various components fit into a small space. At least some
embodiments may also enable heat management that may be advantageous for
a handheld device, which may not be a concern for larger device, such as
fuel cells in automobiles and industrial equipment.

[0103] A further potential advantage that may be realized by one or more
embodiments is that heat, which might conventionally be considered as a
waste product, can be put to good use. In particular, the heat generated
by use of a battery may be recaptured and used to drive a fuel tank or
otherwise facilitate operation of a fuel cell.

[0104] Another advantage that may be realized is that the concepts
described herein may be adapted to a variety of power systems and a
variety of sizes and shapes of mobile electronic devices. The concepts
may also be implemented as an alternative to, or in concert with, other
heat management techniques that may be employed in a mobile electronic
device.

[0105] The foregoing aspects of the mobile electronic device, fuel cell,
fuel tank, energy storage device and other elements are provided for
exemplary purposes only. Those skilled in the art will recognize that
various changes in form, material used and design may be made thereto
without departing from the spirit and scope of the appended claims.

Patent applications by Chee-Ming Jimmy Wu, Toronto CA

Patent applications by David Gerard Rich, Waterloo CA

Patent applications by Taha Shabbir Husain Sutarwala, Toronto CA

Patent applications in class HAVING DIVERSE CELLS OR DIVERSE REMOVABLE CELLS IN A SUPPORT MEANS

Patent applications in all subclasses HAVING DIVERSE CELLS OR DIVERSE REMOVABLE CELLS IN A SUPPORT MEANS